Philips Semiconductors

Product data

P87LPC764

Low power, low price, low pin count (20 pin)

microcontroller with 4 kbyte OTP

2003 Sep 03

45

BIT

SYMBOL

FUNCTION

UCFG2.7, 6

SB2, SB1

EPROM security bits. See table entitled, “EPROM Security Bits” for details.

UCFG2.5–0

—

Reserved for future use.

—

SU01186

—

—

—

—

—

SB1

SB2

0

1

2

3

4

5

6

7

UCFG2

Unprogrammed Value: FFh

Address: FD01h

Figure 37. EPROM System Configuration Byte 2 (UCFG2)

Security Bits

When neither of the security bits are programmed, the code in the EPROM can be verified. When only security bit 1 is programmed, all further

programming of the EPROM is disabled. At that point, only security bit 2 may still be programmed. When both security bits are programmed,

EPROM verify is also disabled.

Table 11. EPROM Security Bits

SB2

SB1

Protection Description

1

1

Both security bits unprogrammed. No program security features enabled. EPROM is programmable and verifiable.

1

0

Only security bit 1 programmed. Further EPROM programming is disabled. Security bit 2 may still be programmed.

0

1

Only security bit 2 programmed. This combination is not supported.

0

0

Both security bits programmed. All EPROM verification and programming are disabled.

ABSOLUTE MAXIMUM RATINGS

PARAMETER

RATING

UNIT

Operating temperature under bias

–55 to +125

°C

Storage temperature range

–65 to +150

°C

0 to +11.0

V

V

20

mA

Power dissipation (based on package heat transfer, not device power consumption)

1.5

W

NOTES:

1. Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and

functional operation of the device at these or any conditions other than those described in the AC and DC Electrical Characteristics section

of this specification are not implied.

2. This product includes circuitry specifically designed for the protection of its internal devices from the damaging effects of excessive static

charge. Nonetheless, it is suggested that conventional precautions be taken to avoid applying greater than the rated maximum.

3. Parameters are valid over operating temperature range unless otherwise specified. All voltages are with respect to VSS unless otherwise noted.